The overall objective of the proposed study is to develop and evaluate an Automated Device for Asthma Monitoring (ADAM). Accurate symptom monitoring is the cornerstone of appropriate asthma management. Symptom monitoring informs patient decisions to initiate necessary self-management behaviors (e.g., adjust medication, alter activity level, alter the surrounding environment or seek medical assistance) as well as the providers' decisions regarding an appropriate treatment course. Current guidelines highlight the importance of ongoing symptom monitoring in improving asthma outcomes and reducing asthma-related disability. Lack of objectivity and poor accuracy have called into question existing symptom monitoring approaches including the use of self-reported symptom monitoring and peak flow meter readings. Adolescence has been recognized as the most challenging period in symptom monitoring primarily due to poor symptom perception and inadequate adherence confounded by developmental characteristics. Therefore, this study specifically targets adolescents. Specific aims are: (1) To develop a biomedical device system, ADAM, that can facilitate non-intrusive, valid and reliable monitoring of asthma symptoms based on the parameters of asthma symptoms including wheeze and cough; (2) To evaluate measurement accuracy and validity of ADAM; and (3) To evaluate the acceptability of ADAM by the study population. This study consists of two phases, a Development Phase and a Validation Phase. During the Development Phase, parameters of wheezes and cough will be identified from the breath sound samples collected from adolescents with active asthma symptoms (N=24). A purpose-built device will be designed for continuous symptom monitoring in real-life environments applying technology that enables selective capturing of wheeze and cough based on the identified parameters as well as activity levels. The device will employ a mobile phone as a platform where raw data inputted from a microphone and a wireless accelerometer are automatically processed, analyzed and stored. Participants will be able to review the summary of data displayed on the screen of the mobile phone. Measurement Theory and Signal Detection Theory guide the research design and analytic approaches of the Validation Phase. For the Validation Phase, data will be collected from an asthma group (n=40) and a non-asthma group (n=40). Accuracy and validity of ADAM will be evaluated using multiple statistical methods including Receiver Operating Characteristic (ROC) curve and correlational analyses, multilevel modeling, and the growth model. Data from ADAM will be compared with Forced Expiratory Volume at 1 second, exhaled fractional nitric oxide, and data from questionnaires including the Asthma Control Test, asthma daily diary, visual analogue scale of symptom perception, and quality of life. User acceptability of the device will be assessed using both research-devised questionnaire and semi-structured qualitative interview. We anticipate that this new device will be reliable and clinically useful, and will improve adolescents' adherence to symptom monitoring. PUBLIC HEALTH RELEVANCE: Asthma is the leading chronic health condition in adolescents. While adequate treatments based on accurate symptom monitoring can prevent or substantially reduce asthma-related negative health consequences, symptom monitoring typically is inadequate or misleading. This study aims to develop and test an innovative device to substantially improve symptom monitoring for adolescents through the application of advanced technology that enables capturing of breath sounds such as wheeze and cough along with activity levels on a daily basis.